Word
luminosity
Phoneticslu·mi·nos·i·ty
UK/lˌuːmɪnˈɒsɪti/
Definition
n. the amount of light that an object gives off. In astronomy, it helps scientists measure how bright a star is compared to our sun.
n. the total amount of electromagnetic radiation emitted by an astronomical object per unit of time. Often used to describe the intrinsic brightness of a star or galaxy.
Examples
“The star has a high luminosity.”
“Astronomers use luminosity to determine the distance to a galaxy by comparing its apparent brightness to its actual output.”
“While the star appears dim to the naked eye, its immense luminosity suggests it is a massive, young object located far beyond our solar system.”
Examples
simple
“The star has a high luminosity.”
contextual
“Astronomers use luminosity to determine the distance to a galaxy by comparing its apparent brightness to its actual output.”
complex
“While the star appears dim to the naked eye, its immense luminosity suggests it is a massive, young object located far beyond our solar system.”
Real-World Examples
“Type Ia supernovae are known to be “standard candles” because we know that their luminosity is the same wherever they are.” “Chandra measured the luminosity during the outburst, and researchers calculated the mass accretion rate necessary to produce that luminosity.” Etymology
Borrowed from French luminosité or else a native formation from luminous + -ity.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
NOUN
ADJECTIVE
Domains
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
- Frequency
- Occasional
- Level
- C1 · Advanced
- Updated
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QR code
englishreference.com/q/luminosity